1. Field of the Invention
The present invention relates to a method for automatically detecting abnormal pulmonary signs in a chest Computed Tomography (hereinafter, referred to as ‘CT’) image, and more particularly, to a method for detecting Ground Glass Opacity (hereinafter, referred to as ‘GGO’) using chest computed tomography, which is able to more accurately detect GGO candidates that show an unclear boundary with the peripheral background and have a low brightness value and a coarse structure as well.
2. Description of the Related Art
Abnormal pulmonary signs that may be detected from chest CT images are largely divided into two groups: pulmonary nodule and GGO.
A pulmonary nodule is referred to as opacity that shows a clear boundary with a normal pulmonary region and has a high CT value. However, GGO is referred to as opacity that shows an unclear boundary with a normal pulmonary region and has a relatively low CT value and a coarse structure.
As a result, the pulmonary nodule is easily discriminated from its peripheral background, but the GGO is not easily discriminated from its peripheral background. Based on these characteristics, computer-aided diagnosis (CAD) programs used to automatically detect a pulmonary nodule have been developed and commercially available. However, a CAD program for automatically detecting GGO is not realized.
In particular, when a CAD program for detecting a pulmonary nodule is used to detect the GGO, too much noise is present in one or more GGO candidates, which lead to the low accuracy in the detection of GGO.